I just hooked up a brand new VDO oil pressure sender and a used VDO oil pressure gauge I have used about 10 years ago...
When I hook up the E to earth and the +12 to 12 Volts
the gauge goes full scale... the wire going to the Sender doesn't do anything....
The sender is located where the normal oil pressure light sender goes by way of a double adaptor...
The sender comes up as an OPEN Circuit on My Meter...
I'll try & find My old sender... I did finally find it somewhere... and check out what it does...

Lee

what was the cost of this Lee ?

is that with the engine hot or cold?

Both COLD and ran engine for about 20 minutes...
I couldn't find the original VDO sender I had, but I did find one out of a Mitsubishi engine and hooked it up.... with the +12 Earth & sender leads connected with the ignition ON,.. The gauge goes full scale and when the engine is started the gauge starts to work....
so it looks like the $34-56 ebay sender unit is NO Good....
It was new in a blister pack..... could have been dropped..

Lee